by Hadley Malcolm, USA TODAY

by Hadley Malcolm, USA TODAY

A strike has crippled two California shipping ports and if it continues, could leave some retailers with sparse shelves toward the end of the holiday shopping season.

About 450 clerical workers represented by the International Longshore and Warehouse Union went on strike a week ago at the ports of Los Angeles and Long Beach. But the work stoppage quickly became more serious as an additional 10,000 port workers refused to cross the striking workers' picket lines.

Despite agreeing to federal mediation Tuesday, the Local 63 Office Clerical Unit says it plans to continue its strike. It has accused the ports' managing group, the Harbor Employers Association, of outsourcing jobs.

The strike has essentially shut down 10 of 14 terminals at the two ports, backing up cargo and delaying shipments.

"The majority of our members have been impacted," says Jon Gold, vice president of supply chain and customs policy for the National Retail Federation. "Cargo that's already arrived is just sitting at the port. Right now there isn't a whole lot they can do."

Gold says the NRF, which has more than 9,000 members, is still working to assess the economic impact. The NRF notes in one of its letters to President Obama calling for an intervention that a 10-day West Coast ports lockout in 2002 cost the economy an estimated $1 billion a day.

According to the Port of Long Beach, the closed terminals have led to more than $3 billion worth of goods sitting on the docks of both affected ports, causing backups and delaying trucks and trains.

"All of the people in the supply chain, or most of them, have stopped working because of this," says Chris Lytle, executive director for the Port of Long Beach. "You have approximately 15 ocean vessels outside at anchor that are waiting for a resolution to this labor problem."

While most retailers already have the majority of their shipments for the holiday season, the work stoppage could affect merchandise coming in just before Christmas, Gold says.

"This time now is when retailers do the big last push to get products to store shelves," he says. "So some of that product is currently being delayed."

Retailers faced a similar situation in September, when threats of a strike by the International Longshoremen's Association along the East Coast had some acting on contingency plans and rerouting shipments to the West Coast to avoid backups during the holiday season.

Those workers returned to the docks but are still in negotiations with the United States Maritime Alliance.

Harbor Employers Association spokesman Steve Getzug denies accusations that the organization is outsourcing jobs. The staffing issue is over whether to fill all jobs that become vacant with full-time workers, he says.

"They say, 'Three people have retired; we want their jobs replaced,' " he says. "We want to make sure the people who occupy those chairs have work to do, as opposed to just occupying chairs. The bottom line is the cargo volumes are not what they used to be."